Peristaltic pump assemblies for use with disposable tubing require the loading of the tubing into the peristaltic pump between a platen and a rotor before use. The rotor is positioned relative to the platen such that rollers located on the periphery of the rotor can intermittently and progressively compress the tubing against the platen to pump fluids through the tubing. In such an arrangement, the space between rollers of the rotor and the platen is less than the diameter of the tubing so that the tubing must be squeezed between the rollers and the platen when loaded into the pump.
One common method of loading the tubing into the pump is to hand-feed the tubing with one hand while hand-rotating the rotor with the other hand. A tool, protrusion or notch located on the rotor may be employed to urge the tubing between the platen and the rollers as the rotor is hand rotated. A problem with hand-feeding the tubing into a peristaltic pump is that both hands must be employed, making the procedure cumbersome.
A less cumbersome approach for loading tubing between the rollers of the rotor and the platen of a peristaltic pump is to either retract the rollers away from the platen or retract the platen away from the rotor with a spring loaded retracting mechanism. This increases the distance between the rollers and the platen to a distance greater than the diameter of the tubing so that the tubing can be easily loaded. A problem with this approach is that a retracting mechanism adds to the cost and complexity of the pump due to an increased number of parts.
Another approach employed for loading tubing within a peristaltic pump is disclosed in U.S. Pat. No. 4,861,242. A loop of tubing extending from a manifold cartridge is loaded into the peristaltic pump by engaging the tubing with a tab which urges the tubing between the platen and the rollers of the rotor while at the same time lowering the loop of tubing with a motor driven linear actuator from an elevation above the platen to an elevation in line with the platen. The upper portion of the rollers have a smaller diameter conical section to cause the tubing to be self-aligning at the larger diameter portion of the rollers. This approach is complex and costly.